1. Research, Development, Test, and Evaluation. Appropriations to fund the efforts performed by contractors and government activities , including procurement of end items, weapons, materiel, components, materials and services required for the development of equipment, material, computer application software, and its development and initial operational test and evaluation. RDT&E also funds the operation of dedicated R&D installations activities for the conduct of R&D programs. 2. Procurement. Appropriations to fund those acquisition programs that have been approved for production, and all costs integral and necessary to deliver a useful end item intended for operational use or inventory upon delivery. 3. Operations & Maintenance. Appropriations to fund expenses such as civilian salaries, travel, minor construction projects, operating military forces, training and education, depot maintenance, stock funds, and base operations support. 4. Military Personnel. Appropriations to fund costs of salaries and other compensation for active and retired military personnel and reserve forces based on end strength. 5. Military Construction. Appropriations to fund major projects such as bases, schools, missile storage facilities, maintenance facilities, medical/dental clinics, libraries, and military family housing. Costs budgeted in the O&M and Military Personnel appropriations are considered expenses. Costs budgeted in the Procurement and Military Construction appropriations are considered investments. Costs budgeted in the RDT&E and Family Housing appropriations include both expenses and investments.